This invention relates to an apparatus for bearing a shaft in a standard comprising a main bearing and a supporting bearing. It is concerned more particularly with theodolites for surveying purposes and with the telescope supports therein.
Theodolites for surveying purposes typically include a base and an upper portion that includes a reasonably rigid standard for the movable support of a telescope. The telescope is attached to a shaft mounted in the standard by a main bearing at one end portion of the shaft and a supporting bearing at the opposite end portion of the shaft. The shaft is usually guided in the main bearing radially as well as in axial direction.
As usually constructed, the shaft mountings for such theodolites have little capability for positional shifts of the supporting bearing such as may occur for example due to mechanical stress equalization or thermal expansion.
This limitation in the capabilities of the shaft mountings has in turn tended to lead manufacturers to use expensive and time consuming procedures for assembly and adjusting the theodolites. Yet such disadvantages have been tolerated as necessary to the maintenance of the desired accuracy in the measurements to be made by the completed theodolite.